Ratchet screwdrivers, or other ratcheting mechanisms for fastener drivers such as screwdrivers, nut drivers, and the like, typically are constructed so that the ratcheting mechanism is built directly into the screwdriver, so that the two are sold together, or so that a specialized screwdriver is ncessary in order to cooperate with the ratching assembly.
According to one aspect of the present invention, a drive assembly for a screwdriver is provided that is extremely versatile. The drive assembly according to the invention may be used with a wide variety of conventional screwdrivers that are already on the market. This allows the individual who already has sets of screwdrivers, nut drivers, and the like to merely purchase the driver assembly, and to utilize the driver assembly with a wide variety of such conventional screwdrivers, nut drivers, or the like. The driving assembly according to the invention simply slips over a conventional existing handle of a screwdriver, and thereby quickly and easily changes the conventional screwdriver into a ratcheting screwdriver.
According to another aspect of the present invention, a particular ratchet means is provided, the ratchet means particularly adapted for use with a drive assembly according to the invention. The ratchet means includes a single, toothed ratchet wheel rotatable about an axis of rotation, and a plurality of pawls, each pawl having two toothed lobes. All the pawls are mounted about a common axis of rotation, which is generally parallel to the axis of rotation of the ratchet wheel. A selector knob, with a spring extending therefrom and engaging the pawls, determines which lobe of each pawl is to be biased into operative association with the toothed ratchet wheel, thereby to select a direction of ratcheting rotation. The teeth of adjacent pawls are displaced with respect to each other so as to minimize the amount of rotation between stops of the ratchet wheel for a given tooth spacing of the wheel.
It is the primary object of the present invention to provide for the simple, effective, and versatile ratcheting of a screwdriver or the like. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.